Hydrocarbon fuel compositions

ABSTRACT

Liquid hydrocarbon distillate fuel compositions, especially gasolines, containing mineral and organic acid salts of hydrocarbyl polyamides effectively nullify and/or inhibit fouling of vital parts of internal combustion engines.

ilmte States Patent 11 1 1111 3,785,799 Strang Jan. 15, 1974 [54] HYDROCARBON'FUEL COMPOSITIONS 2,527,889 10/]950 Moore et al. 44/66 2,622,018 12/1952 White et al. 44/66 UX [75] lnvemor- Am smmg Amsterdam 2,939,842 6/1960 Thompson 44/71 Netherlands 3,542,679 11/1970 Cyba 44 72 Assignee Comp y, New ork, Mehmedbasmh [22] Filed: Dec. 29, 1971 E Primary ExaminerDaniel Wyman [21] Appl' 213723 Assistant Examiner-Mrs. Y. H. Smith Att0rneyHenry C. Geller et al. [30] Foreign Application Priority Data Dec. 30, l970 Great Britain 6l769/7O [57] ABSTRACT [52] US. C1 44/66, 44/71, 44/72,

, 44/ 44/ 4 Liquid hydrocarbon distillate fuel compositions, espe- [51] lint. Cl .1. C10! 1/26 Ciany gasolines containing mineral and organic acid Fleld of Search 71, 72, alt of hydrocarby] polyamides effectively and- /or inhibit fouling of vital parts of internal combustion [56] References Cited engines UNITED STATES PATENTS 2,487,190 11/1949 Smithet al 44/66 4 Claims, No Drawings ll HYDROCARBON FUEL COMPOSIITHONS BACKGROUND OF THE INVENTION The invention relates to fuel compositions having improved properties. ln particular, it relates to gasoline compositions which effectively inhibit and/or prevent the fouling of the fuel and inlet system of internal combustion engines.

One means of combating airpollution is to reduce the emission of hydrocarbons by gasoline engines, due, inter ali'a, to crankcase ventilation. This ventilation is necessary to prevent dilution and contamination of the lubricating oil by unburnt or partly burnt gasoline components leaking from the combustion chamber along the piston and cylinder walls into the crankcase. The crankcase is ventilated by a forced draft as a result of which components'known as blow-by gases, find their way into the atmosphere. To reduce this type of emission, some engine manufacturers have provided the engine with means for returning the mixture of blow-by gases and air to the inlet system preceding the carburetor, for instance, to the air filter. This measure, however, causes fouling of the fuel and inlet system, which, in turn causesthe engine to malfunction. This tends to increase the concentration or unburnt and partly burnt hydrocarbons-in the exhaust gases. I

For non-surface vehicles such as supersonic aircraft, the fuels (called aviation turbine fuels)-have to meet very stringent thermal stability requirements; they not only must absorb the large amounts of heat generated, at high speeds, clue to air friction, but must also remain stable if they are to function properly.

These high temperatures further entail the risk of interreaction of the hydrocarbon components present in the aviation fuel composition with the resultant formation of products which may deposit on vital engine parts. This can cause serious problems, such as clogging of filters, control systems and fuel supply lines. Therefore, ,thermal stability constitutes one of the major problems of fuels for supersonic aircraft.

Previous attempts have been made to solve these problems. As a rule, however, the usual oxidation inhibitors have proven entirely unsatisfactory. In certain cases inhibitors have even promoted the formation of deposits.

SUMMARY OF THE INVENTION A class of polyamine compounds has now been found which, when incorporated as additives into a liquid hydrocarbon distillate fuel in minor amounts, effectively act to inhibit and prevent engine fouling. When added to a gasoline, these polyamine compounds effectively counteract engine fouling and specifically inhibit foulingof the carburetor and to a certain extent also fouling of other parts of the fuel and inlet system, such as valves and valve rods. When incorporated into aviation turbine fuels, they stabilize these fuels against deterioration at high temperatures, and are able to minimize the formation of noxious products in the fuel system of theaircraft engine.

Thecompounds concerned are mineral and organic acid salts of polyamines, the polyamine having at least one monovalent hydrocarbon group of at least 50 carbon atoms and at least one monovalent hydrocarbon group with no more than carbon atoms bound directly to different nitrogen atoms and the number of hydrogen atoms bound to nitrogen being smaller than the number of nitrogen atoms present in the polyamine whereby one of the amino nitrogens is a tertiary nitrogen.

The invention therefore relates particularly to liquid hydrocarbon distillate fuel compositions comprising a major proportion of a fuel and a minor proportion of one or more mineral or organic acid salts of polyamines, the polyamine having at least one monovalent hydrocarbon group of at least 50 carbon atoms and at least one monovalent hydrocarbon group with no more than 5 carbons atoms bound directly to different nitrogens and the number of hydrogen atoms bound to nitrogen being smaller than the number of nitrogen atoms present in the polyamine whereby one of the amino nitrogens is a tertiary nitrogen.

DESCRIPTION OF PREFERRED EMBODIMENTS The polyamines from which the novel salts of the invention are derived, having at least one monovalent hydrocarbon group of at least 50 carbon atoms and at least one monovalenthydrocar bon group with no more than 5 carbon atoms bounddirectly to different nitrogens and the number of hydrogen atoms bound to nitrogen being smaller than the number of nitrogen atoms presentin the polyamine whereby one of the amino nitrogens is a tertiary nitrogen, are further to be denoted in this specification as polyamines A.

The polyamines A,.may if desired, contain more than one of each of the monovalent hydrocarbon groups of at least 50 carbon atoms and of the monovalent hydrocarbon groups with no more than 5 carbon atoms. However, it is preferred that the polyamines A contain one and only one monovalent hydrocarbon group of at least 50 carbon atoms. The monovalent hydrocarbon groups may be bound to the same nitrogen atom or to different nitrogen atoms, but it is preferred that the monovalent hydrocarbon group of at least .50 carbon atoms be bound to a different nitrogen atom from that to which the hydrocarbon group with no more than 5 carbon atoms is bound. Here, by monovalent hydrocarbon group should be understood a monovalent hydrocarbyl radical, built up substantially from carbon and hydrogen, in which, however, dependent on the chosen method of preparation of the polyamines A, a minor amount of one or more other elements, e.g. halogen, may be present. Preferred though is a polyamine A consisting only of carbon, hydrogenand nitrogen. Examples of suitable hydrocarbyl groups are alkyl or alkenyl groups derived from alkanes or alkenes with a straight or a branched carbon chain, which may carry aromatic or cycloaliphatic hydrocarbon substituents. The hydrocarbon groups of at least 50 carbon atoms are preferably non-substituted alkenyl or alkyl groups, such as polyethylene groups, polypropylene groups, polybutenyl groups and polyisobutenyl groups. Preferred are polyamines A having the hydrocarbon groups of at least 50 carbon atoms contain less than 500 carbon atoms, in particular less than 200 carbon atoms. Particularly preferred are hydrocarbon groups with at least 50 and less than 200 carbon atoms, said hydrocarbon groups being branched alkyl or alkenyl groups. As hydrocarbon groups of at least 50 carbon atoms, polyisobutenyl groups are preferred most.

The hydrocarbon groups with no more than 5 carbon atoms are preferably alkyl groups with an unbranched carbon chain. Preferred are methyl, ethyl and propyl. Methyl groups are particularly preferred.

In the polyamines A from which the salts of the invention are derived the number of hydrogen atoms which are bound to nitrogen should be smaller than the number of nitrogen atoms present in the polyamines A. Preferred are polyamines A wherein the number of hydrogen atoms which are abound to nitrogen is about half the number of nitrogen atoms present in the polyamine A molecule.

The polyamines A can be considered to be derived from polyamines which contain neither a monovalent hydrocarbon group of at least 50 carbon atoms, nor a monovalent hydrocarbon group with no more than 5 carbon atoms bound directly to nitrogen, by replacing the monovalent hydrocarbon groups by a hydrogen atom. These amines will be referred to hereinbelow as polyamines B; consequently, the polyamines B can be considered to act as carriers for said monovalent hydrocarbon groups. The polyamines B may be either aliphatic or aromatic polyamines. Both diamines and higher amines are suitable. Examples of suitable diamines are ethylene-l ,Z-diamine, propylenel,2-diamine, propylene-1,3-diamine, the butylene diamines and benzene-l ,4-diamine. Examples of suitable higher amines are the polyalkylenepolyamines, such as the polyethylenepolyamines and the polypropylenepolyamines. Specific examples of the polyethylenepolyamines are diethylenetriamine, triethylenetetramine and tetraethylenepentamine, pentaethylenehexamine and higher polyamines with a molecular weight above 1,000. As polyamines B alkylene diamines are preferred, especially polymethylene-a,wdiamine and particularly propylene-1,3-diamine. The most preferred polyamine A is N-polyisobutenyl-N', N '-dimethylpropylene-l ,3-diamine wherein the polyisobutenyl group has at least 50 and less than 200 carbon atoms.

The polyamines A may be prepared in any desired manner, for instance, by allowing a polyamine which already carries the desired number of monovalent hydrocarbon groups with no more than 5 carbon atoms but which does not carry a monovalent hydrocarbon group of at least 50 carbon atoms (further to be referred to as polyamine C) to react with a halogencontaining hydrocarbon of at least 50 carbon atoms in the molecule. One may suitably start from a chlorinecontaining hydrocarbon obtained by chlorination substitition of an alkene of at least 50 carbon atoms in the molecule and a double bond in the terminal position whose beta-carbon atom carries a methyl group. The chlorination can suitably be carried out with an amount of chlorine that is just sufficient or somewhat in excess to convert the alkene into the corresponding alkenyl chloride. One may start, for instance, from polyisobutene, which is allowed to react either as such or in an inert solvent with an amount of chlorine that is just sufficient or somewhat in excess to form polyisobutenyl chloride. The reaction between the halogencontaining hydrocarbon and the polyamine C is carried out at a temperature between 20 and 200 C, preferably in the presence of an inert solvent. In the reaction between a halogen-containing hydrocarbon and a polyamine C, hydrogen halide is formed in addition to the desired additive, which hydrogen halide combines with the polyamine C used as starting material. Hence, unless special measures are taken, the polyamine C has to be present in a large excess. As it is desirable for the amount of polyamine C required for the preparation of the polyamines A to be kept as small as possible, it is preferred that the reaction be carried out in the presence of a hydrogen-halide acceptor that differs both from the polyamine C used as starting material and from the polyamine A formed. Examples of hydrogenhalide acceptors suitable for use in the preparation of the present additives are, for instance, carbonates, bicarbonates, oxides and hydroxides of, for example, the alkali and alkaline earth metals. Favorable results are obtained by using sodium carbonate or potassium carbonate as hydrogen halide acceptor.

The molar ratio in which the halogen-containing hydrocarbon of at least 50 carbon atoms in the molecule and the polyamine C are allowed to react depends on the number of hydrocarbon groups to be introduced. For the preparation of preferred polyamines A in which substantially a single hydrocarbon group of at least 50 carbon atoms is bound directly to one of the nitrogen atoms of the polyamine, preferably at most 2 gram molecules of the starting polyamine C are used per gram atom of halogen present in the halogen-containing hydrocarbon.

If the polyamines A are prepared by a process comprising the reaction of a halogen-containing hydrocarbon of at least 50 carbon atoms in the molecule with a polyamine C in which one or more monovalent hydrocarbon groups of no more than 5 carbon atoms are bound directly to nitrogen, very suitable polyamines C are N,N-dimethylpropylene-l ,3-diamine, N,N- diethylpropylene-l ,B-diamine, N,N-dipropylpropylene- 1,3-diamine, N,N-dibutyl-propylenel,3-diamine, N,- N-dipentylpropylene-l ,3-diamine, N-methyl-N-propylpropylene-1,3-diamine, N-ethy'l-N-methylpropylene- 1,3-diamine, and the like. Especially preferred as polyamine C is N,N-dimethylpropylene-l,B-diamine.

Excellent results have been obtained by the reaction of polyisobutenyl chlorides in which the average number of carbon atoms amounted from about to about with an N,N-di (lower alkyl)-(lower alkylene )-a,wdiamine, such as N,N-dimethylpropylene-l,3-diamine, in which reaction about 1.3 gram molecules of a polyamine C were used per gram atom of chlorine present in the polyisobutenyl chloride. In this way polyamines A were prepared wherein two lower alkyl (alkyl of l to 4 carbon atoms) groups, e.g., two methyl groups, and substantially one polyisobutenyl group of from about 80 to about 120 carbon atoms were bound directly to nitrogen and wherein the number of hydrogen atoms which were bound to nitrogen was substantially half the number of nitrogen atoms present in the polyamine A.

acids derived from phosphorous and/or sulfur.

Suitable carboxylic acids include aromatic carboxylic acids and aliphatic carboxylic acids. The carboxylic acids may contain one or more carboxylic groups. Representative examples of aromatic carboxylic acids inlcude the phthalic acids; benzoic acid; alkylbenzoic acids; such as the methylbenzoic acids; salicylic acids and alkylsalicylic acids; such as diisopropylsalicylic acid; and alkylsalicylic acids which contain at least one alkyl substituent of from 8 to 22, and preferably 14 to 18, carbon atoms, if desired together with one or more shorter alkyl groups such as methyl groups, tert-butyl groups and the like, the'preparation of which is disclosed, for example, in U.S. Pat No. 3,013,868. Aliphatic mono-, diand poly-carboxylic acids are also useful. Representative examples of dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, and the like. A suitable tricarboxylic acid is citric acid. Representative monocarboxylic acids which are useful are lower aliphatic monocarboxylic acids, such as acetic acid, propionic acid, butyric acid, isobutyric acid and valeric acid. Preferred are higher aliphatic monocarboxylic acids,i.e., those containing from 6 to 20 carbon atoms, such as lauric acid, palmitic acid, stearic acid, isostearic acid, oleic acid and the like. These acids may be branched, and they may, if desired, containtertiary or quaternary carbon atoms, i.e., a-branched saturated monocarboxylic acids. Suitable acids containing tertiary carbon atoms are carboxylic acids which can be obtained by reaction of olefms having at least three carbon atoms with carbon monoxide and water in the presence of nickel or cobalt salts. Highly useful acids containing quaternary carbon atoms are carboxylic acids which can be obtained by'reaction of olefms of from 4 to 19, and preferably from 8m 18, carbon atoms with carbon monoxide and water in the presence of an acid catalyst, e.g., a mixture of phosphoric acid, boron trifluoride and water such as described in [1.8. Pat. No. 3,291,858, US. Pat. No. 3,294,727 and US. Pat No. 3,059,005. A preferred group comprises a,a-dialykl monocarboxylic acids of 4 to 20, and especially 9 to 19, carbon atoms in the molecule.

Acids derived from sulfur which are used with advantage as the acids from which the polyamine A salts are derived are aliphatic, aromatic and alkyl-substituted aromatic sulfonic acids. Examples of aliphatic sulfonic acids are sulfonic acids containing a hydrocarbyl chain, e.g., hydrocarbyl of from 8 to 20 carbon atoms. Suitable aromatic sulfonic acids are benzenesulfonic acid, naphthalenesulfonic acid and the like. Particularly useful are alkyl-substituted aromatic sulfonic acids of from 7 to 26 carbon atoms, such as p-toluenesulfonic acid and the like. Preferred are those wherein the alkyl substituent contains from 6 to 20, and especially from 9 to 12, carbon atoms and wherein the alkylsubstituent is branched. Acids derived from sulfur which are also suitably used as the acids from which the polyamine A salts are derived are half-esters of sulfuric acid such as half esters of sulfuric acid and alcohols of from 8 to 18 carbon atoms.

Acids derived from phosphorous, which are used advantageously as the acids from which the polyamine A salts are derived, include organic acids derived from trivalent or pentavalent phosphorous, such as phosphonic acids, phosphinic acids, monoor diesters of phosphoric acid, and monoesters of phosphonic acids.

Representative acids derived from monoand diesters of phosphoric acid are the monoand diphenylesters and the monoand di-alkyl esters of phosphoric acid wherein the alkyl chains contain from 1 to 20, and preferably from 12 to 16, carbon atoms, such as monomethyl phosphate, dimethyl phosphate, monoethyl phosphate, diethyl phosphate, monodecyl phosphate, didecyl phosphate, monotridecyl phosphate, ditridecyl phosphate, monohexadecyl phosphate, dihexadecyl phosphate, monooctadecyl phosphate, dioctadecyl phosphate and the like. Mixed esters of phos phoric acid may also be used, such as methyl ethyl phosphate, octyl decyl phosphate, decyl dodecyl phosphate, hexadecyl octadecyl phosphate and the like. The esters of phosphoric acid may also be derived from diand poly-valent alcohols.

Suitable acids derived from phosphonic acid are alkylphosphonic and arylphosphonic acids. Suitable aryl groups of the arylpho'sphonic acids include phenyl and tolyl groups. Suitable alkyl groups of the alkylphosphonic acids are methyl, ethyl, butyl, hexyl, octyl, decyl, dodecyl, hexadecyl, octadecyl groups and the like. Representative examples of useful phosphonic acids are phenylphosphonic acid, methylphosphonic acid, ethylphosphonic acid, dodecylphosphonic acid, and the like.

Monoesters of substituted and unsubstituted phosphonic acids, from which the polyamine A salts of the invention can suitably be derived, are monoesters of phosphonic acids with several types of mono-, diand polyvalent alcohols and phenols, such as methyl alcohol, ethyl alcohol, the butyl alcohols, hexyl alcohol, octyl alcohol, 2-ethyl-hexyl alcohol, decyl alcohol, dodecyl alcohol, hexadecyl alcohol, octadecyl alcohol, phenol and the cresols. Representative examples of these types of esters are methyl hydrogen phosphonate, ethyl hydrogen phosphonate, methyl hydrogen phenylphosphonate, methyl hydrogen ethylphosphonate, octyl hydrogen methylphosphonate, octadecyl hydrogen ethylphosphonate, phenyl hydrogen ethylphosphonate, ethyl hydrogen octylphosphonate and the like.

Suitable acids derived from phosphonic acids are monoand di-alkylphosphinic acids, such as monoand di-methylphosphonic acid, monoand diethylphosphinic acid, monoand di-butylphosphinic acid, monoand di-octylphosphinic acid, monoand di-decylphosphinic acid, monoand dididodecylphosphinic acid, monoand dioctadecylphosphinic acid, methyl ethylphosphinic acid, octyl decylphosphinic acid, dodecyl octadecylphosphinic acid, and monoand di-arylphosphinic acids of 6 to 12 carbon atoms, such as mono phenylphosphinic acid, in particular diphenylphosphinic acid, and alkyl arylphosphinic acids, such as ethyl phenylphosphinic acid, methyl tolylphosphinic acid, dodecyl phenylphosphinic acid and'octadecyl phenylphosphinic acid.

Acids derived from phosphorous which contain sulfur atoms attached to the phosphorus atom are also very suitable; e.g., in the acids mentioned which are derived from phosphoric acid, phosphonic acid and phosphinic acid one or more oxygen atoms can be replaced by sulfur atoms.

Mixtures of acids may also be used in order to form the polyamine A salts.

A particularly preferred group of acids includes sulfuric acid, phosphoric acid, aliphatic monocarboxylic acid of 6 to 20 carbon atoms, a,a-dialkyl monocarboxylic acids of 9 to 19 carbon atoms, alkyl-substituted aromatic sulfonic acid of 7 to 26 carbon atoms, salicylic acid, alkylsalicylic acid of at least one alkyl substituent of 14 to 18 carbon atoms, mono to di C alkyl ester of phosphoric acid and aryl phosphinic acid of 6 to 12 carbon atoms.

The salts can very conveniently be prepared by mixing the acid and the polyamine A in the appropriate amounts, if desired in a solvent. This solvent may be removed from the polyamine A salts formed, e.g., by distillation. The polyamine A salts can be prepared in a pure form by addition of an equivalent amount of acid to the polyamine A, but in general an excess of polyamine A will be used. In this way mixtures of the salt and unconverted polyamine A will be obtained. The number of gram equivalents of acids used per gram equivalent basic nitrogen of polyamine A originally present may vary between wide limits, preferably between 0.40 and 0.95; the mixtures of polyamine A salt and polyamine A thus obtained are suitably used as additives in the fuel compositions.

The polyamine A salts are advantageously used as additives in fuel compositions. Mixtures of polyamine A salts can also be used in the fuel compositions of the invention.

Aviation turbine fuel can be defined as a hydrocarbon oil having a Reid vapour pressure below 3 lb/sq inch at 100 F and a final boiling point below 325 C.

Gasoline can be defined as a mixture of hydrocarbon having a boiling range determined according to ASTM method D 86 between about 30 and 210 C.

The polyamine salts of the invention, added in a small amount, for example to an aviation turbine fuel, impart to that fuel stability against high temperatures. The aviation turbine fuels used may have been freed of sulfur by means of hydrotreating, or the sulfur compounds may have been converted by means of an acid (e.g., sulfuric acid) treatment. When the salts of the invention are added in a small amount to a gasoline, they exhibit a high activity as cleanliness agents for the carburetor as well as for other parts of the inlet system, such as the inlet valves and the inlet valve rods.

The concentration of the polyamine A salts together with polyamine A, if any, in the fuel may vary within wide limits. In general, the desired effects are obtained when the amount added to a fuel is from 0.001 to percent by weight and preferably from 0.001 to 0.1 percent by weight. The additives may be added to the fuel as such or in the form of a concentrate obtained, for instance, by mixing the additive with a small amount of a hydrocarbon oil, such as a distillate fuel or a lubricating oil. In addition to a major amount of fuel and a minor amount of the present additive, the fuel compositions of the invention may contain minor amounts of other additives, by which the quality of the fuel is further improved. For example, the fuel compositions of the invention may also contain agents improving the ignition, such as tetra-alkylleads, scavenging agents, anti-icing additives, anti-oxidants, conductivity-improving agents, metal-deactivating compounds, and the like.

Metal deactivators suitable for fuels, in particular aviation turbine fuels, are compounds having the formula described in British Pat. 931,436, issued July 17, 1963. A very active metal deactivator, in particular a copper deactivator, in this class of compounds is l,3-di(2-pyridyl)-iminoisoindoline. Especially shitable metal deactivators, which may with special advantage be used in the fuel compositions of the invention, are compounds belonging to the class of the N ,N-disalicylidene-1,2-diaminoalkanes, preferably N,N -disalicylidene-l ,2-diaminopropane. The amount of metal deactivators which may be present in the fuel compositions of the invention may vary between wide limits; amounts between 0.0001 and 0.01 percent by weight are preferred.

Antioxidants, particularly phenolic antioxidants such as 2,6-ditert-butyl-4-methylphenol and 2,4-dimethyl-6 tert-butylphenol, may also be present in the fuels of the invention, preferably in amounts between 0.0005 and 0.05 percent by weight.

Conductivity improving agents, which decrease the tendency of spontaneous ignition during handling of fuels, in particular during pumping of aviation turbine fuels, may also be incorporated in the fuels. Suitable conductivity-improving agents consist of a mixture of the calcium or-barium salt of dialkyl (e.g., dioctyl) sodium sulphosuccinate, chromium salts of alkyl (e.g., C -C salicylic acids and a copolymer of alkyl methacrylates (e.g., lauryl and/or stearyl methacrylate) and a vinylpyridine (e.g., 2-methyl-5-vinylpyridine and/or 4-viny1pyridine).

EXAMPLE I A polyamine A was prepared as follows:

Polyisobutene with a molecular weight of 1,280 was dissolved in isooctane. After addition of a crystal of iodine to this solution, chlorine was introduced at room temperature until the color of the solution faded. Subsequently, the solvent was vaporized. The residue contained 2.84 percent w chlorine, corresponding to a monochloro product.

A mixture of 123.2 g of the above-prepared polyisobutenyl chloride, ml toluene and 10 g pulverized potassium carbonate was heated to 130 C in a nitrogen atmosphere with stirring and subsequently, while the mixture was being stirred, 13.0 g N,N-dimethylpropy- 1ene-1,3-diamine was added dropwise over a period of 5 hours. After that an additional amount of 4 g pulverized potassium carbonate was added and the reaction mixture, while being stirred, was kept at 130 C for 15 hours. After cooling down, the reaction product was taken up in a 60/80 gasoline and washed with water until the washwater was free from chlorine. The reaction product was isolated by vaporizing the solvent. The N'-polyisobutenyl-N,N dimethylpropylene-1,3- diamine obtained weighed 124.5 g and had a nitrogen content of 1.24 percent by weight.

The polyamine A and the acid concerned were separately dissolved in a suitable solvent. The salts were prepared by adding per gram equivalent of basic nitrogen present in the polyamine A 0.9 and 0.5 gram equivalent of acid. The solvent was removed under reduced pressure at a temperature of at most C.

a) one mole of phosphoric acid is taken to be equal to two gram equivalents.

EXAMPLE 11 Some of the polyamine A salts were tested in the ISD apparatus described in paper 660783 of the Society of Automotive Engineers by A. A. Johnston and E. Dimitroff. The fuel used was a gasoline which contained 150 ppm spindle oil. The amount of the mixture of polyamine A and polyamine A salts added to this fuel was 150 ppm. During each experiment the temperature of the deposit tube was kept at about 200 C, the air flow was maintained at 33 cfh, and 100 ml gasoline was used at a rate of about 2.0 ml/min. At the end of the experiment the deposit tube was washed with heptane, and the deposit weight determined. As can be seen from Table II, the gasolines containing the polyamine A salts according to the invention show less deposit tendencies than the undoped gasoline.

EXAMPLE Ill In a way similar to that described in Example I a number of salts according to the invention were prepared from the polyamine A described in Example I. In Table III are recorded the number of g. eq. acid used per g. eq. basic nitrogen in polyamine A. The products obtained were incorporated in a mineral lubricating oil with a viscosity of about 4 08 at 99 C to a concentration of 40 percent by weight. These concentrates were dissolved in a leaded gasoline producing a gasoline composition containing 100 ppm of the salt and the polyamine A together. These gasoline compositions were tested in a Sunbeam Talbot engine. In this test the inlet system fouling is determined on the basis of fouling of the inlet valves and the inlet valve rods. The test is carried out on a Sunbeam Talbot engine with a piston displacement of 2264 cm, a compression ratio of 6.45:1, and a maximum capacity of 70 bhp at 4,000 rpm. Before the test was started, the engine, including the two carburetors, was cleaned whereupon the engine was kept in continuous operation for 32 hours at a speed of 1,500 rpm, a capacity of 15 bhp and a fuel consumption of 5.0 kg per hour. After the test had been finished, the fouling of the inlet valves and the inlet valve rods was evaluated, and the cleanliness performance rated in a system 0-100 where'0 clean.

In Table III the percentage improvement of the cleanliness performance rating of the gasoline compositions of the invention over the cleanliness performance rating of the same gasoline without the salt of the invention and the polyamine A are recorded. It can be seen that all gasoline compositions containing the salts of the invention showed a much better cleanliness performance than the gasoline without these additives.

Table III acid used in polyamine g. eq. acid used per g. improvement in A salt preparation eq. basic nitrogen in cleanliness polyamine A performance (96) stearic acid 0.9 92 isostearic acid 0.9 89 caprilic acid 0.9 93 salicylic acid 0.9 96 p-toluenesulfonic acid 0.9 62

diphenylphosphinic acid 0.9 64 sulfuric acid 0.9 71 phosphoric acid 0.9 94

phosphoric acid, aliphatic monocarboxylic acid of 6 to 20 carbon atoms, alpha,alpha-dialkyl monocarboxylic acid of 9 to 19 carbon atoms, alkyl-substituted aromatic sulfonic acid of 7 to 26 carbon atoms, salicylic acid, alkylsalicylic acid of at least one alkyl substituent of 14 to 18 carbon atoms, mono to di C1246 alkyl ester of phosphoric acid, and aryl phosphinic acid of 6 to 12 carbon atoms.

2. The composition of claim 11 in which the alkyl groups are methyl.

3. The composition of claim l in which the amount of the salt of the diamine is between 0.001 and 0.1 percent by weight.

41. Gasoline containing between 0.001 and 0.1 percent by weight of a mineral or organic acid salt of N'- polyisobutenyl-N,N-dimethylpropylene-1 ,3-diamine wherein the polyisobutenyl group has at least 50 and less than 200 carbon atoms and said acid is selected from the group consisting of sulfuric acid, phosphoric acid, aliphatic monocarboxylic acid of 6 to 20 carbon atoms, alpha,alpha-dialkyl monocarboxylic acid of 9 to 19 carbon atoms, alkyl-substituted aromatic sulfonic acid of 7 to 26 carbon atoms, salicylic acid, alkylsalicylic acid of at least one alkyl substituent of 14 to 18 carbon atoms, mono to dl C1246 alkyl ester of phosphoric acid, and aryl phosphinic acid of 6 to 12 carbon atoms. 4 

2. The composition of claim 1 in which the alkyl groups are methyl.
 3. The composition of claim 1 in which the amount of the salt of the diamine is between 0.001 and 0.1 percent by weight.
 4. Gasoline containing between 0.001 and 0.1 percent by weight of a mineral or organic acid salt of N''-polyisobutenyl-N,N-dimethylpropylene-1,3-diamine wherein the polyisobutenyl group has at least 50 and less than 200 carbon atoms and said acid is selected from the group consisting of sulfuric acid, phosphoric acid, aliphatic monocarboxylic acid of 6 to 20 carbon atoms, alpha,alpha-dialkyl monocarboxylic acid of 9 to 19 carbon atoms, alkyl-substituted aromatic sulfonic acid of 7 to 26 carbon atoms, salicylic acid, alkylsalicylic acid of at least one alkyl substituent of 14 to 18 carbon atoms, mono to dl C12-16 alkyl ester of phosphoric acid, and aryl phosphinic acid of 6 to 12 carbon atoms. 